An oil boom is transforming the eastern Mediterranean — and changing relationships, especially with Israel

In 2007, Mathios Rigas spent $1.13 million to buy a near-dormant oil well in Greece with a license that was about to expire. The engineer-turned-banker hired a Venezuelan petroleum chemist, the only person he had met in Greece who knew about oil and gas.

He called his company “Energean,” a play on the words energy and the Aegean Sea.

It paid off. The Prinos oilfield, Greece’s only oil-producing asset, held more reserves than thought and is now producing thousands of barrels a day. In 2016, armed with the experience, Rigas placed another bet and bought the rights to develop the Karish and Tanin natural gas fields off the coast of Israel — a country that bigger oil and natural gas exploration companies were avoiding because it could affect their business with Arab countries or Iran.